1. Field of the Invention
The present invention generally relates to a display device. Particularly, the present invention relates to a display device having curved surface.
2. Description of the Prior Art
Flat panel display is extensively used in a variety of apparatuses having display function. For example, apparatuses such as display devices, computers, communication devices, and home appliances are equipped with flat panel display. Flat panel display may have display panel of various types such as liquid crystal display panel and plasma display panel. Furthermore, in addition to the general flat structure, display panels nowadays could be made lighter and even have curved shape or be flexible to facilitate versatile design of display or to develop different application of flat panel display.
As FIG. 1A shows, a display device 800 could include a display panel 810 and a light case 820. A light source 830 such as light-emitting diodes are disposed in the light case 820, wherein the light case 830 has a certain height to ensure a distance between the light source 830 and the display panel 810. The distance is associated with light mixing of the light emitted from the light source and therefore influences brightness or illumination uniformity of image. To ensure image quality, the distance is determined based on a ratio of the distance to a distance “d” between adjacent light sources that must be greater than or equal to 0.3 (i.e. the distance divided by “d”≧0.3). However, with regard to a display panel having curved shape, image quality is influenced since the distance between the light source and the display panel is not fixed and light-mixing distance is not fixed. As the conventional display device shown in FIG. 1, in which the distance “d” between any adjacent light sources is the same, when the distance “D2” divided by “d” equals 0.3 (i.e. D2/d=0.3), the distance “D1” divided by “d” will be less than 0.3 (i.e. D1/d<0.3). As such, even light around the location having the distance “D2” is well-mixed, light around the location having the distance “D1” will not be mixed sufficiently and the mura phenomena in image will occur. In order to ensure the distance “D1” divided by “d” equal to 0.3 (i.e. D1/d=0.3), the number of light sources has to be increased to compensate the shorter light-mixing distance and maintain image quality; however, the cost accordingly rises.